An Interpolative Analytical Cache Model with Application to Performance-Power Design Space Exploration

Caches are known to consume up to half of all system power in embedded processors. Co-optimizing performance and power of the cache subsystems is therefore an important step in the design of embedded systems, especially those employing application specific instruction processors. In this project, we propose an analytical cache model that succinctly captures the miss performance of an application over the entire cache parameter space. Unlike exhaustive trace driven simulation, our model requires that the program be simulated once so that a few key characteristics can be obtained. Using these application-dependent characteristics, the model can span the entire cache parameter space consisting of cache sizes, associativity and cache block sizes. In our unified model, we are able to cater for direct-mapped, set and fully associative instruction, data and unified caches. Validation against full trace-driven simulations shows that our model has a high degree of fidelity. Finally, we show how the model can be coupled with a power model for caches such that one can very quickly decide on pareto-optimal performance-power design points for rapid design space exploration.

高速缓存优化的并行连接算法

由于嵌套循环连接操作过程中存在较大的高速缓存缺失,严重影响了连接查询的性能。提出了一种基于缓冲的高速缓存参数无关的嵌套循环并行连接算法。通过高速缓存参数无关和缓冲技术,提高了连接算法的空间局部性和时间局部性。理论分析和实验结果表明,高速缓存优化后的串行连接算法的性能是原来的2倍,其并行算法效果近似线性加速比。

模型检测MESIF Cache一致性协议

在处理器从单核向多核演进的过程中,为了获得更好的性能和可扩展性,适用于多核处理器系统的Cache一致性协议变得越来越复杂。Cache一致性协议的验证一直是模型检测在工业界主要应用之一,被工业界和学术界关注。相对传统方法而言,微结构级的模型检测能够描述和验证更多的协议细节。利用NuSMV工具对Intel公司的MESIF Cache一致性协议进行模型检测在微结构层次上进行了建模,并对该协议进行模型检测,试验结果证明了此方法的有效性。

Covariance Averaging for Improved Estimation and Portfolio Allocation

We propose a new method for estimating the covariance matrix of a multivariate time series of nancial returns. The method is based on estimating sample covariances from overlapping windows of observations which are then appropriately weighted to obtain the nal covariance estimate. We extend the idea of (model) covariance averaging o ered in the covariance shrinkage approach by means of greater ease of use, exibility and robustness in averaging information over different data segments. The suggested approach does not su er from the curse of dimensionality and can be used without problems of either approximation or any demand for numerical optimization.

UUm Modelo Exploratório, Baseado nas Comunidades Linux, para Desenvolvimento da Tecnologia da Informação no Brasil

presente trabalho objetiva construir um Modelo Exploratório de desenvolvimento de tecnologia da informação, aplicável no Brasil, tendo como referência as formas de organização do trabalho e da produção das comunidades Linux. O Modelo deve ser aplicado em ambiente Internet, ou em outras redes de telecomunicação. Por essa razão, utiliza métodos e técnicas de aprendizado à distância e e-Iearning. A construção do Modelo apoia-se, como alicerce teórico fundamental, no conceito de convivialidade de Illich (1976), no entendimento de Inose e Pierce (1984) sobre comunidades de interesse e democratização da produção de software, nos estudos de Malone (1997, 1998) referentes a modelos de organização em rede, nos estudos de Weber (2000) sobre comunidades de interesse online, na metodologia de capacitação "Pensamento Digital" de Joia (1999-1, 1999-2) e na estratégia pedagógico-metodológica do Australian National Training Authority (T AFE/SA). No entanto, as pesquisas de Matesco (2000, 2001) tomaram exeqüível a idéia da construção do Modelo, tendo que vista que o Modelo Exploratório proposto aplica-se, preferencialmente, a países, regiões, empresas ou organizações dependentes tecnologicamente de seus parceiros negociais e com escassez de recursos para aplicar em pesquisa e desenvolvimento. O caminho metodológico para a construção do Modelo inicia-se com uma sucinta abordagem sobre o sistema operacional Linux, a descrição das formas de organização das comunidades Linux e a identificação das formas de organização do trabalho e da produção no Fordismo-Taylorismo e no pós-Fordismo. Situa o funcionamento das comunidades Linux em relação a essas formas de organização. Descreve o processo de formação do conhecimento no aprendizado à distância e no elearning. Aborda a experiência de outros países com o Linux e com as comunidades Linux. Principalmente, o sucesso obtido pelos países nórdicos em absorção de tecnologia. A seguir, fundamentando-se em duas pesquisas de Matesco (2000,2001), analisa a dependência tecnológica do Brasil e propõe o Modelo Exploratório, cujo objetivo é, prioritariamente, colaborar para a redução dessa dependência, por meio de um processo de formação de conhecimento, baseado no aprendizado à distância e e-Iearning do Linux e na propagação de comunidades Linux, empregando-se o modelo de organização em rede.

Modeling Commercial Knowledge to Develop Advanced Agent-based Marketplaces for E-commerce

This paper argues about the utility of advanced knowledge-based techniques to develop web-based applications that help consumers in finding products within marketplaces in e-commerce. In particular, we describe the idea of model-based approach to develop a shopping agent that dynamically configures a product according to the needs and preferences of customers. Finally, the paper summarizes the advantages provided by this approach.

The role of the humanities in the Bologna idea of a university : learning from the american model?. 'El papel de la humanidad en la idea de Bolonia de una universidad : ¿el aprender del modelo americano?'.

Resumen tomado de la publicación. Monográfico con el título: El proceso de Bolonia : dinámicas y desafíos de la enseñanza superior en Europa a comienzos de una nueva época

Analytic model of a cache-only memory architecture

An approximate analytic model of a shared memory multiprocessor with a Cache Only Memory Architecture (COMA), the busbased Data Difussion Machine (DDM), is presented and validated. It describes the timing and interference in the system as a function of the hardware, the protocols, the topology and the workload. Model results have been compared to results from an independent simulator. The comparison shows good model accuracy specially for non-saturated systems, where the errors in response times and device utilizations are independent of the number of processors and remain below 10% in 90% of the simulations. Therefore, the model can be used as an average performance prediction tool that avoids expensive simulations in the design of systems with many processors.

Semantic technologies in idea management systems: a model for interoperability, linking and filtering

Abstract Idea Management Systems are web applications that implement the notion of open innovation though crowdsourcing. Typically, organizations use those kind of systems to connect to large communities in order to gather ideas for improvement of products or services. Originating from simple suggestion boxes, Idea Management Systems advanced beyond collecting ideas and aspire to be a knowledge management solution capable to select best ideas via collaborative as well as expert assessment methods. In practice, however, the contemporary systems still face a number of problems usually related to information overflow and recognizing questionable quality of submissions with reasonable time and effort allocation. This thesis focuses on idea assessment problem area and contributes a number of solutions that allow to filter, compare and evaluate ideas submitted into an Idea Management System. With respect to Idea Management System interoperability the thesis proposes theoretical model of Idea Life Cycle and formalizes it as the Gi2MO ontology which enables to go beyond the boundaries of a single system to compare and assess innovation in an organization wide or market wide context. Furthermore, based on the ontology, the thesis builds a number of solutions for improving idea assessment via: community opinion analysis (MARL), annotation of idea characteristics (Gi2MO Types) and study of idea relationships (Gi2MO Links). The main achievements of the thesis are: application of theoretical innovation models for practice of Idea Management to successfully recognize the differentiation between communities, opinion metrics and their recognition as a new tool for idea assessment, discovery of new relationship types between ideas and their impact on idea clustering. Finally, the thesis outcome is establishment of Gi2MO Project that serves as an incubator for Idea Management solutions and mature open-source software alternatives for the widely available commercial suites. From the academic point of view the project delivers resources to undertake experiments in the Idea Management Systems area and managed to become a forum that gathered a number of academic and industrial partners. Resumen Los Sistemas de Gestión de Ideas son aplicaciones Web que implementan el concepto de innovación abierta con técnicas de crowdsourcing. Típicamente, las organizaciones utilizan ese tipo de sistemas para conectar con comunidades grandes y así recoger ideas sobre cómo mejorar productos o servicios. Los Sistemas de Gestión de Ideas lian avanzado más allá de recoger simplemente ideas de buzones de sugerencias y ahora aspiran ser una solución de gestión de conocimiento capaz de seleccionar las mejores ideas por medio de técnicas colaborativas, así como métodos de evaluación llevados a cabo por expertos. Sin embargo, en la práctica, los sistemas contemporáneos todavía se enfrentan a una serie de problemas, que, por lo general, están relacionados con la sobrecarga de información y el reconocimiento de las ideas de dudosa calidad con la asignación de un tiempo y un esfuerzo razonables. Esta tesis se centra en el área de la evaluación de ideas y aporta una serie de soluciones que permiten filtrar, comparar y evaluar las ideas publicadas en un Sistema de Gestión de Ideas. Con respecto a la interoperabilidad de los Sistemas de Gestión de Ideas, la tesis propone un modelo teórico del Ciclo de Vida de la Idea y lo formaliza como la ontología Gi2MO que permite ir más allá de los límites de un sistema único para comparar y evaluar la innovación en un contexto amplio dentro de cualquier organización o mercado. Por otra parte, basado en la ontología, la tesis desarrolla una serie de soluciones para mejorar la evaluación de las ideas a través de: análisis de las opiniones de la comunidad (MARL), la anotación de las características de las ideas (Gi2MO Types) y el estudio de las relaciones de las ideas (Gi2MO Links). Los logros principales de la tesis son: la aplicación de los modelos teóricos de innovación para la práctica de Sistemas de Gestión de Ideas para reconocer las diferenciasentre comu¬nidades, métricas de opiniones de comunidad y su reconocimiento como una nueva herramienta para la evaluación de ideas, el descubrimiento de nuevos tipos de relaciones entre ideas y su impacto en la agrupación de estas. Por último, el resultado de tesis es el establecimiento de proyecto Gi2MO que sirve como incubadora de soluciones para Gestión de Ideas y herramientas de código abierto ya maduras como alternativas a otros sistemas comerciales. Desde el punto de vista académico, el proyecto ha provisto de recursos a ciertos experimentos en el área de Sistemas de Gestión de Ideas y logró convertirse en un foro que reunión para un número de socios tanto académicos como industriales.

Venture idea newness, relatedness and performance in nascent ventures

Principal Topic The study of the origin and characteristics of venture ideas - or ''opportunities'' as they are often called - and their contextual fit are key research goals in entrepreneurship (Davidsson, 2004). We define venture idea as ''the core ideas of an entrepreneur about what to sell, how to sell, whom to sell and how an entrepreneur acquire or produce the product or service which he/she sells'' for the purpose of this study. When realized the venture idea becomes a ''business model''. Even though venture ideas are central to entrepreneurship yet its characteristics and their effect to the entrepreneurial process is mysterious. According to Schumpeter (1934) entrepreneurs could creatively destruct the existing market condition by introducing new product/service, new production methods, new markets, and new sources of supply and reorganization of industries. The introduction, development and use of new ideas are generally called as ''innovation'' (Damanpour & Wischnevsky, 2006) and ''newness'' is a property of innovation and is a relative term which means that the degree of unfamiliarity of venture idea either to a firm or to a market. However Schumpeter's (1934) discusses five different types of newness, indicating that type of newness is an important issue. More recently, Shane and Venkataraman (2000) called for research taking into consideration not only the variation of characteristics of individuals but also heterogeneity of venture ideas, Empirically, Samuelson (2001, 2004) investigated process differences between innovative venture ideas and imitative venture ideas. However, he used only a crude dichotomy regarding the venture idea newness. According to Davidsson, (2004) as entrepreneurs could introduce new economic activities ranging from pure imitation to being new to the entire world market, highlighting that newness is a matter of degree. Dahlqvist (2007) examined the venture idea newness and made and attempt at more refined assessment of the degree and type of newness of venture idea. Building on these predecessors our study refines the assessment of venture idea newness by measuring the degree of venture idea newness (new to the world, new to the market, substantially improved while not entirely new, and imitation) for four different types of newness (product/service, method of production, method of promotion, and customer/target market). We then related type and degree of newness to the pace of progress in nascent venturing process. We hypothesize that newness will slow down the business creation process. Shane & Venkataraman (2000) introduced entrepreneurship as the nexus of opportunities and individuals. In line with this some scholars has investigated the relationship between individuals and opportunities. For example Shane (2000) investigates the relatedness between individuals' prior knowledge and identification of opportunities. Shepherd & DeTinne (2005) identified that there is a positive relationship between potential financial reward and the identification of innovative venture ideas. Sarasvathy's 'Effectuation Theory'' assumes high degree of relatedness with founders' skills, knowledge and resources in the selection of venture ideas. However entrepreneurship literature is scant with analyses of how this relatedness affects to the progress of venturing process. Therefore, we assess the venture ideas' degree of relatedness to prior knowledge and resources, and relate these, too, to the pace of progress in nascent venturing process. We hypothesize that relatedness will increase the speed of business creation. Methodology For this study we will compare early findings from data collected through the Comprehensive Australian Study of Entrepreneurial Emergence (CAUSEE). CAUSEE is a longitudinal study whose primary objective is to uncover the factors that initiate, hinder and facilitate the process of emergence and development of new firms. Data were collected from a representative sample of some 30,000 households in Australia using random digit dialing (RDD) telephone survey interviews. Through the first round of data collection identified 600 entrepreneurs who are currently involved in the business start-up process. The unit of the analysis is the emerging venture, with the respondent acting as its spokesperson. The study methodology allows researchers to identify ventures in early stages of creation and to longitudinally follow their progression through data collection periods over time. Our measures of newness build on previous work by Dahlqvist (2007). Our adapted version was developed over two pre-tests with about 80 participants in each. The measures of relatedness were developed through the two rounds of pre-testing. The pace of progress in the venture creation process is assessed with the help of time-stamped gestation activities; a technique developed in the Panel Study of Entrepreneurial Dynamics (PSED). Results and Implications We hypothesized that venture idea newness slows down the venturing process whereas relatedness facilitates the venturing process. Results of 600 nascent entrepreneurs in Australia indicated that there is marginal support for the hypothesis that relatedness assists the gestation progress. Newness is significant but is the opposite sign to the hypothesized. The results give number of implications for researchers, business founders, consultants and policy makers in terms of better knowledge of the venture creation process.

A FR.E.S.H idea

This paper explores the possibility of including human factoring in a business process model. The importance of doing so is twofold: (1) The organization becomes transparent in its processes as all participants (human, activities and events) are identifiable. (2) Including human factoring allows organizations to hire accordingly to the process needs. (3) Human factoring alleviates the current work related stress that is being encountered. (4) Enable quicker transition for newer employees into job scope. This was made possible by including a human behaviour layer in between pools within a process to depict human behaviour and feeling. Future work includes having a human thought symbol and a human interaction symbol included into the Business Process Modelling Notation (BPMN).

Model round-trip engineering

In the quest for shorter time-to-market, higher quality and reduced cost, model-driven software development has emerged as a promising approach to software engineering. The central idea is to promote models to first-class citizens in the development process. Starting from a set of very abstract models in the early stage of the development, they are refined into more concrete models and finally, as a last step, into code. As early phases of development focus on different concepts compared to later stages, various modelling languages are employed to most accurately capture the concepts and relations under discussion. In light of this refinement process, translating between modelling languages becomes a time-consuming and error-prone necessity. This is remedied by model transformations providing support for reusing and automating recurring translation efforts. These transformations typically can only be used to translate a source model into a target model, but not vice versa. This poses a problem if the target model is subject to change. In this case the models get out of sync and therefore do not constitute a coherent description of the software system anymore, leading to erroneous results in later stages. This is a serious threat to the promised benefits of quality, cost-saving, and time-to-market. Therefore, providing a means to restore synchronisation after changes to models is crucial if the model-driven vision is to be realised. This process of reflecting changes made to a target model back to the source model is commonly known as Round-Trip Engineering (RTE). While there are a number of approaches to this problem, they impose restrictions on the nature of the model transformation. Typically, in order for a transformation to be reversed, for every change to the target model there must be exactly one change to the source model. While this makes synchronisation relatively “easy”, it is ill-suited for many practically relevant transformations as they do not have this one-to-one character. To overcome these issues and to provide a more general approach to RTE, this thesis puts forward an approach in two stages. First, a formal understanding of model synchronisation on the basis of non-injective transformations (where a number of different source models can correspond to the same target model) is established. Second, detailed techniques are devised that allow the implementation of this understanding of synchronisation. A formal underpinning for these techniques is drawn from abductive logic reasoning, which allows the inference of explanations from an observation in the context of a background theory. As non-injective transformations are the subject of this research, there might be a number of changes to the source model that all equally reflect a certain target model change. To help guide the procedure in finding “good” source changes, model metrics and heuristics are investigated. Combining abductive reasoning with best-first search and a “suitable” heuristic enables efficient computation of a number of “good” source changes. With this procedure Round-Trip Engineering of non-injective transformations can be supported.